Oxidative stress leads to membrane lipid peroxidation, which yields products causing variable degrees of detrimental oxidative modifications in cells. Reactive oxygen species (ROS) are the key regulators in this process and induce lipid peroxidation in Escherichia coli. Application of nonthermal (cold) plasma is increasingly used for inactivation of surface contaminants. Recently, we reported a successful application of nonthermal plasma, using a floating-electrode dielectric-barrier discharge (FE-DBD) technique for rapid inactivation of bacterial contaminants in normal atmospheric air (S. G. Joshi et al., Am. J. Infect. Control 38:293-301, 2010). In the present report, we demonstrate that FE-DBD plasma-mediated inactivation involves membrane lipid peroxidation in E. coli. Dose-dependent ROS, such as singlet oxygen and hydrogen peroxide-like species generated during plasma-induced oxidative stress, were responsible for membrane lipid peroxidation, and ROS scavengers, such as ␣-tocopherol (vitamin E), were able to significantly inhibit the extent of lipid peroxidation and oxidative DNA damage. These findings indicate that this is a major mechanism involved in FE-DBD plasma-mediated inactivation of bacteria.Nonthermal (cold) dielectric-barrier discharge (DBD) atmospheric-pressure plasma is widely under investigation for use as an alternative sterilization and disinfection method in the fields of biology and medicine. Most recently, we demonstrated that Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus in both their planktonic form and in biofilms are rapidly inactivated by nonthermal DBD plasma using a floating-electrode technique (11). Complete inactivation of E. coli was seen in less than 120 s when E. coli was present in its planktonic form, and complete inactivation occurred in about 180 s when it was in the biofilm form, making this technique attractive for sterilization processes. E. coli is one of the most common Gram-negative bacterial contaminants responsible for hospital-acquired infections (HAI) and one of the most widely studied organisms in the laboratory and therefore is a good choice to track various oxidative-stress pathways.A DBD plasma-generating probe is an apparatus that generates microsecond-long, high-voltage-pulsed cold plasma between the primary electrode covered with a quartz surface and the surface of the biological sample, which serves as a second electrode. The high-voltage electrode is completely covered with a dielectric barrier, which makes it safe for sterilization applications, and the nature of the applied microsecond pulses do not elevate the surface temperature above 28°C. In the floating-electrode DBD (FE-DBD) plasma setup, the second electrode (biological sample) is not grounded and remains at a floating potential. Discharge ignites when the powered electrode approaches the surface to be treated at a distance (discharge gap) less than about 3 mm, depending on the form, duration, and polarity of the driving voltage, and it is safe to apply...

How are memories transferred from short-term to long-term storage? Systems-level memory consolidation is thought to be dependent on the coordinated interplay of cortical slow waves, thalamo-cortical sleep spindles and hippocampal ripple oscillations. However, it is currently unclear how the selective interaction of these cardinal sleep oscillations is organized to support information reactivation and transfer. Here, using human intracranial recordings, we demonstrate that the prefrontal cortex plays a key role in organizing the ripple-mediated information transfer during non-rapid eye movement (NREM) sleep. We reveal a temporally precise form of coupling between prefrontal slow-wave and spindle oscillations, which actively dictates the hippocampal-neocortical dialogue and information transfer. Our results suggest a model of the human sleeping brain in which rapid bidirectional interactions, triggered by the prefrontal cortex, mediate hippocampal activation to optimally time subsequent information transfer to the neocortex during NREM sleep.

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Mounting evidence suggests that during conscious states, the electrodynamics of the cortex are poised near a critical point or phase transition and that this near-critical behavior supports the vast flow of information through cortical networks during conscious states. Here, we empirically identify a mathematically specific critical point near which waking cortical oscillatory dynamics operate, which is known as the edge-of-chaos critical point, or the boundary between stability and chaos. We do so by applying the recently developed modified 0-1 chaos test to electrocorticography (ECoG) and magnetoencephalography (MEG) recordings from the cortices of humans and macaques across normal waking, generalized seizure, anesthesia, and psychedelic states. Our evidence suggests that cortical information processing is disrupted during unconscious states because of a transition of low-frequency cortical electric oscillations away from this critical point; conversely, we show that psychedelics may increase the information richness of cortical activity by tuning low-frequency cortical oscillations closer to this critical point. Finally, we analyze clinical electroencephalography (EEG) recordings from patients with disorders of consciousness (DOC) and show that assessing the proximity of slow cortical oscillatory electrodynamics to the edge-of-chaos critical point may be useful as an index of consciousness in the clinical setting.

Conversions of signaling gradients into sharp ''all-or-none'' borders are fundamental to tissue and organismal development. However, whether such conversions can be meaningfully reduced to dissociated cells in culture has been uncertain. Here we describe ultrasensitivity, the phenomenon equivalent to an all-or-none response, in dissociated neural precursor cells (NPCs) exposed to bone morphogenetic protein 4 (Bmp4). NPC ultrasensitivity is evident at the population and single-cell levels based on Msx1 induction, a well known Bmp target response, and occurs in the context of gene expression changes consistent with Bmp4 activity as a morphogen. Dissociated NPCs also display immediate early kinetics and irreversibility for Msx1 induction after brief Bmp4 exposure, which are attractive features for initial border formation. Relevance to border formation in vivo is provided by Bmp4 gain-of-function studies in explants and evidence for single-cell ultrasensitivity in normal and mutant Bmp gradient contexts in the developing forebrain. Together, these studies demonstrate relatively simple, robust, and reducible cell-intrinsic properties that contribute to developmental border formation within a signaling gradient.dorsal midline ͉ Msx ͉ neural stem cell

The VITOM system for spinal surgery provides outstanding image quality and an ease of manipulation rivaling the OM. There were no statistically significant differences in mean operative room time, intraoperative complications, or total hospital length of stay when using this novel system in several common spinal procedures relative to the OM.

Deep brain stimulation (DBS) is becoming increasingly central in the treatment of patients with Parkinson’s disease and other movement disorders. Recent developments in DBS lead and implantable pulse generator design provide increased flexibility for programming, potentially improving the therapeutic benefit of stimulation. Directional DBS leads may increase the therapeutic window of stimulation by providing a means of avoiding current spread to structures that might give rise to stimulation-related side effects. Similarly, control of current to individual contacts on a DBS lead allows for shaping of the electric field produced between multiple active contacts. The following review aims to describe the recent developments in DBS system technology and the features of each commercially available DBS system. The advantages of each system are reviewed, and general considerations for choosing the most appropriate system are discussed.